Cross-platform app development cost for technology & saas

There is no single figure, and quoting one would be the least useful thing this page could do — the same pairing spans several-fold depending on scope, compliance and how many surfaces you ship. What this page gives you instead is what the pairing demands: the regimes that may apply, the systems of record you will be asked to integrate with, the device matrix and the release path. The calculator below is already fixed to Cross-platform and technology & saas — answer what is left and it returns a cost range, hours, timeline, team and running costs for your scope.

Because technology & saas brings its own obligations before you write a feature: SOC 2 Type II, GDPR, CCPA / CPRA may apply, you will be asked to integrate with systems like Stripe and Auth0 / Clerk / Cognito, and there are typically 6 distinct roles rather than one. The platform contributes its own separate costs — the device matrix, App Store & Google Play review — and those are independent of the industry.

In this model a single native app is the baseline. Two native apps cost about 1.7× that, because the second platform reuses the product thinking, API and design but repeats the implementation and its own test matrix. One cross-platform codebase costs about 1.24× the baseline plus fixed bridge hours. So against two native builds you save roughly 25–30% of client engineering — a real saving, but smaller than the "half price, one codebase" pitch suggests, because testing does not halve.

Flutter renders its own widgets, so the UI is highly consistent across platforms and animation-heavy interfaces behave predictably; the cost is that nothing looks natively platform-idiomatic unless you make it. React Native uses native components and shares language and often code with a web front end, which matters a great deal if you already have a React team. For a greenfield mobile-only product, Flutter is usually the more predictable build. For a team already writing TypeScript, React Native is usually the cheaper hire.

Typically $30,000–$70,000 over the equivalent single-tenant product, and considerably more if you retrofit it. The cost is not a tenant column on your tables — it is that every query, cache key, background job, export and test must be tenant-aware, and that a single missed filter is a data breach rather than a bug. That raises your security and QA bar permanently. Design for it from the start even if you launch with one customer.

When a deal depends on it, not before — but design so you can. SAML SSO, SCIM provisioning, audit logs and role granularity total $80,000–$180,000 of engineering, and SOC 2 Type II adds $20,000–$45,000 in auditor fees on top of the evidence work. Building it speculatively is premature. Building your auth layer and data model so it can be added without a rewrite costs almost nothing and saves a painful quarter later.